Neurological Functional Connectivity in Unilateral Coronal Synostosis: A Side-Based Comparison

Abstract

Purpose: Unicoronal synostosis (UCS) has been associated with reading, language, and social dysfunction. Limited brain function connectivity studies exist for UCS with none devoted to comparing outcomes by side of synostosis (left versus right-sided UCS). Methods: Twelve patients with surgically treated UCS, 7 rightsided and 5 left-sided, were age matched to healthy controls. Resting state functional MRI was acquired in a 3T Siemens TIM Trio scanner (Erlangen, Germany). Data was collected with intrinsic connectivity distribution and seed-connectivity analysis using BioImage Suite (Yale School of Medicine). Region of interest analysis was performed based on Brodmann areas related to emotional, executive, language, motor, and visuo-spatial function. Significance was set at P < 0.05. Results: Compared to controls, all UCS patients demonstrated decreased connectivity in areas of the parietal and temporal cortices responsible for visuo-motor coordination and language function. Right UCS patients demonstrated decreased intrinsic connectivity in regions related to complex motor movement and proprioception relative to control subjects. Left UCS patients demonstrated decreased seed connectivity between regions of the parietal lobe and occipital lobe related to motor coordination, visual function, and language compared to right UCS patients. Conclusion: Unicoronal synostosis had decreased functional connectivity in regions associated with memory, visual information processing, and motor function. Moreover, left-sided UCS had decreased connectivity in circuits for motor coordination and language when compared to right-sided UCS. This study provides data suggestive of long-term sequelae of UCS that varies by sidedness, which may be responsible for neurocognitive impairments found in previous cognitive analyses.

Systematic Review of the Clinical and Experimental Research Assessing the Effects of Craniosynostosis on the Brain

“…[14][15][16][17][18][19] Moreover, a paucity of studies were published to date that clarified the etiopathogenesis of CS on the brain microstructure and its connectivity, to address the controversy mentioned above. [20][21][22][23] Conversely, the current studies did not draw conclusive impressions regarding the neural foundations of such impairment in the microstructure of the brain; moreover, in humans, imaging strategies such as diffusion tensor imaging (DTI) and functional magnetic resonance (fMRI) have been used to address these issues. 24,25 Therefore, it is paramount to obtain stronger evidence on this matter, to allow the treating pediatric neurosurgeons and the parents to better decide whether the surgical indication for CS provides significant mitigation of the neurocognitive impairments.…”

“…As postulated by Schoenemann et al,27 the complexity of the brain arises from its connectivity. Moreover, the network of the brain has been the most studied topic in the last decade in patients affected by CS because of the possibility of combining the information provided by brain imaging with the results of neurocognitive tests 20,22,23. To date, several imaging modalities have been applied to the study of patients with CS to study the structure of the white matter or its function.…”

“…Moreover, the network of the brain has been the most studied topic in the last decade in patients affected by CS because of the possibility of combining the information provided by brain imaging with the results of neurocognitive tests. 20,22,23 To date, several imaging modalities have been applied to the study of patients with CS to study the structure of the white matter or its function. Diffusion tensor imaging was able to detect structural abnormalities according to parameters such as fractional anisotropy (FA) and diffusivity properties, among which the mean diffusivity (MD), axial diffusivity, and radial diffusivity are frequently used.…”

“…Although surgical approaches have been consolidated as an efficient way to avoid serious consequences in brain development in patients with CS, some reports have identified subtle neurocognitive deficits in patients even after cranial reconstruction secondary to CS during childhood; these reports also described visual-spatial deficits, language impairment, and behavioral problems, reinforcing the argument that the goal of the surgical treatment of this disease is cosmetic 14–19. Moreover, a paucity of studies were published to date that clarified the etiopathogenesis of CS on the brain microstructure and its connectivity, to address the controversy mentioned above 20–23…”